In recent times, weighing scales, especially of the type used in the produce section of supermarkets to weigh vegetables, have been of the digital type with lighted digital displays showing numbers to a customer. Such scales, whether used as produce scales, or dairy counter scales, or delicatessen counter scales, are safer and better if there are no wires or cords running from the scale to electrical outlets which supply the electrical energy. Wires or cords are dangerous to customers who walk near them in the store, not only from the standpoint of danger from electrical shock, but also from the danger of a mechanical obstruction which might trip them.
Accordingly, it has been desired to eliminate the electrical cords which extend from electronic weighing scales, and to provide cordless weighing scales.
Cordless weighing scales may be actuated by batteries, such as dry cell batteries, or rechargeable batteries, or solar batteries which are directly energized by ambient light. However, batteries have presented a number of problems. The dry cell batteries do not last very long before they need to be replaced. The rechargeable batteries need to be recharged often. The ambient light energized batteries, or solar batteries, require expensive circuitry because it is necessary to provide high impedances and other circuit parameters to keep the consumption of energy low while at the same time limiting the susceptibility of such circuitry to jitter during periods of decreasing light (for instance, with the onset of evening hours).